Results of a combined photoelectron spectroscopy and first-principles density-functional study of SiN - clusters in the size range 20 e N e 45 are reported and discussed. Evidence for a prolate-to-near-spherical shape transition at N ) 27 is presented. It is shown that the tricapped-trigonal-prism (TTP) structural motif Si9 found in most low-lying clusters SiN -, 9 e N e 19, is replaced or augmented by a series of structural motifs consisting of a bulklike “adamantane” fragment plus a magic-number cluster (Si6, Si7, Si10) or TTP Si9 in low-lying prolate clusters SiN -, N g 20. For 28 e N e 45, almost all low-lying near-spherical clusters SiN -adopt “stuffed-cage”-like structures where the cages are homologous to carbon fullerenes in the sense that they are composed of only five- and six-membered rings. However the arrangement of the “stuffing” atoms is not yet diamondlike.
Revised: March 7, 2006 |
Published: January 26, 2006
Citation
Bai J., L. Cui, J. Wang, S. Yoo, X. Li, J. Jellinek, and C. Koehler, et al. 2006.Structural Evolution of Anionic Silicon Clusters SiN (20=N=45).Journal of Physical Chemistry A 110, no. 3:908-912.PNNL-SA-48670.